I want to deactivate a custom perl ETL module that I am no longer using.  The ETL module was created and activated quite a while ago using Integration Studio.  Previously I have deactivated ETL modules and then deleted them from the repository using Integration Studio but when I try to deactivate this ETL module I get a message saying 'The operation could not be performed due to an error'. I have checked and I don't think the module is being used by any ETLs so I cannot see an obvious reason why I can't deactivate it.

Is there another way I can deactivate the ETL module?  I have looked at the documentation for the ETL Development Kit but that only seems to explain how to deactivate ETL modules that were activated using the ETL Development Kit.